Corrosion resistant aluminum alloy

ABSTRACT

An aluminum alloy composition includes a corrosion resistant aluminum alloy selected from the group consisting of: a 1xxx series aluminum alloy, a 3xxx series aluminum alloy, and a 5xxx series aluminum alloy. The corrosion resistant aluminum alloy includes not greater than 0.04 wt. % Fe, not greater than 3 wt. % Mg, an effective amount of a corrosion resistant additive, and the balance being aluminum.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of International Patent Application No. PCT/US2017/066053, filed Dec. 13, 2017, which claims the benefit of priority of U.S. Provisional Patent Application No. 62/434,739, filed Dec. 15, 2016, each of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

Broadly, the present disclosure is directed towards aluminum anode alloys with improved corrosion resistance.

BACKGROUND

Clean, sustainable energy is a global concern. Electrochemical cells are utilized as clean, sustainable energy. By commercially deploying these sustainable forms of energy, it is possible to lower the global dependence on fossil fuels.

SUMMARY OF THE INVENTION

Utilizing aluminum alloy compositions as an electrode (anode) in an electrochemical cell can be evaluated by quantifying and/or qualifying two phenomena: (1) the anodic reaction and (2) the corrosion reaction of the aluminum alloy composition. In the anodic reaction, aluminum reacts with hydroxyl ions which results in the release of electrons, the primary and desirable product of an electrochemical cell. Without being bound by any particular mechanism or theory, it is believed that in the corrosion reaction, the aluminum in the anode material is oxidized in the presence of water and as the oxygen in the water reacts with the aluminum, aluminum oxide is formed, generating hydrogen gas (e.g. a byproduct of the corrosion reaction of the aluminum alloy composition). In the corrosion reaction, aluminum is consumed without contributing to the production of (creating) electrical energy in the electrochemical cell. Without being bound by a particular mechanism or theory, it is believed that by reducing the amount of corrosion reaction, more electrode material is available to participate in the anodic reaction, contributing to the longevity of the anode and production of electrical energy by the electrochemical cell.

The extent of corrosion reaction, i.e. the amount of hydrogen generated for an aluminum alloy used as an anode, is a function of electrolyte temperatures and current densities in the electrochemical cell. As operating temperatures and applied current vary for the operation of the cell, so too does the aluminum alloy composition experience varying instances of high anodic reaction and high corrosion reaction windows within the operating parameters/ranges of the electrolytic cell.

One or more embodiments of the present disclosure are directed towards aluminum alloy compositions configured with corrosion resistant additives present in an effective amount to reduce the hydrogen generation in an electrochemical cell thereby controlling (i.e. reducing and/or eliminating) the corrosion reaction. The present disclosure is directed towards aluminum alloys with improved corrosion resistance when employed as an electrode in an electrochemical cell. More specifically, the present disclosure is directed towards aluminum anode alloys having compositions including not greater than 3 wt. % Mg (e.g. 2.5 wt. % Mg), not greater than 400 ppm Fe (e.g. <60 ppm), and corrosion resistance additions of an effective amount of: Zn, Ga, and/or combinations thereof (e.g. configured in the aluminum alloy as alloying elements).

Without being bound by any particular mechanism or theory, it is believed that additions (e.g. small and/or trace additions) of corrosion resistant additives: Zn and Ga, individually or in combination, in a 1xxx, 3xxx, or 5xxx series aluminum alloy composition will provide improved corrosion resistance (e.g. reduced corrosion) as compared to an aluminum alloy composition (of the same series) that does not have these additions (e.g. alloying elements).

Moreover, without being bound by any particular mechanism or theory, it is believed that additions (e.g. trace additions and or small additions) of Zn, Ga, individually or in combination in the aluminum alloy composition (e.g. as alloying elements to a 1xxx, 3xxx, or 5xxx series aluminum alloy) will improve corrosion resistance of the anode in the electrochemical cell during a wide range of electrochemical cell operating conditions (e.g. temperature and current efficiency) as compared to an aluminum alloy without such corrosion resistant additives. In particular, it is believed that additions of these components will provide significant improvement to corrosion resistance at electrochemical cell operating conditions of high corrosion (e.g. low current densities and/or low temperatures) for conventional aluminum alloy compositions without such additions.

In one aspect, an aluminum alloy is provided, comprising: an effective amount of a corrosion resistant additive. As used herein, an “effective amount” in this embodiment is a large enough quantity to provide an improved corrosion resistance in the aluminum alloy composition (e.g. measurable, observable, and/or quantifiable). In some embodiments, improved corrosion resistance is evaluated in an electrochemical cell test.

As used herein, “corrosion resistant additive” refers to an addition of a component to an aluminum alloy (e.g. 1xxx, 3xxx, or 5xxx series aluminum alloys) in order to impart corrosion resistance (e.g. reduce corrosion when evaluated as an electrode in an electrochemical cell) as compared to the alloy's corrosion without such additions.

In one aspect, the corrosion resistant additive is Zn.

In one embodiment, the corrosion resistant additive is Ga.

In one embodiment, the corrosion resistant additive is Zn and Ga.

In one embodiment, the corrosion resistant additive is selected from the group consisting of: Zn, Ga, and combinations thereof.

In one embodiment, the corrosion resistant aluminum alloy has: an effective amount of a corrosion resistant additive; not greater than 0.04 wt % Fe; not greater than 3 wt. % Mg; and the balance being aluminum.

In one embodiment, the corrosion resistant aluminum alloy is a 1xxx series, 3xxx series, or 5xxx series aluminum alloy having: an effective amount of a corrosion resistant additive; not greater than 0.04 wt % Fe; not greater than 3 wt. % Mg; and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy is a 1xxx series, 3xxx series or 5xxx series aluminum alloy having: an effective amount of a corrosion resistant additive selected from the group consisting of: Zn, Ga, and combinations thereof; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy is a 1xxx series, 3xxx series, or 5xxx series aluminum alloy having: not greater than 0.05 wt. % of a corrosion resistant additive selected from the group consisting of: Zn, Ga, and combinations thereof, where at least some (e.g. an effective amount of) corrosion resistant additive is present; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy comprises: 0.0005 wt. % to not greater than 0.06 wt. % of a corrosion resistant additive, where at least some (e.g. an effective amount of) corrosion resistant additive is present; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg (e.g. 0.01 wt. % to not greater than 3 wt. %); and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy comprises: 0.0005 wt. % to not greater than 0.06 wt. % of a corrosion resistant additive selected from the group consisting of: Zn, Ga, and combinations thereof, where at least some (e.g. an effective amount of) corrosion resistant additive is present; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg (e.g. 0.01 wt. % to not greater than 3 wt. %); and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy is a 1xxx series, 3xxx series, or 5xxx series aluminum alloy having: at least 0.002 wt. % to not greater than 0.05 wt. % of a corrosion resistant additive selected from the group consisting of: Zn, Ga, and combinations thereof; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy is a 1xxx series, 3xxx series, or 5xxx series aluminum alloy having: at least 0.002 wt. % to not greater than 0.025 wt. % of a corrosion resistant additive selected from the group consisting of: Zn, Ga, and combinations thereof; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy is a 1xxx series, 3xxx series, or 5xxx series aluminum alloy having: at least 0.005 wt. % to not greater than 0.0250 wt. % of a corrosion resistant additive selected from the group consisting of: Zn, Ga, and combinations thereof; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy is a 1xxx series, 3xxx series, or 5xxx series aluminum alloy having: at least 0.01 wt. % to not greater than 0.05 wt. % of a corrosion resistant additive selected from the group consisting of: Zn, Ga, and combinations thereof; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; and the balance being aluminum (e.g. and unavoidable impurities).

In one embodiment, the corrosion resistant aluminum alloy is a 1xxx series, 3xxx series, or 5xxx series aluminum alloy having: at least 0.015 wt. % to not greater than 0.03 wt. % of a corrosion resistant additive selected from the group consisting of: Zn, Ga, and combinations thereof; not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; and the balance being aluminum (e.g. and unavoidable impurities). In one or more of the aforementioned embodiments, when Zn and Ga are utilized in combination, the amount of corrosion resistant additive is not greater than 0.1 wt. %.

In some embodiments, the effective amount of corrosion resistant additive is at least 5 ppm; at least 10 ppm; at least 15 ppm; at least 20 ppm; at least 50 ppm; at least 100 ppm; at least 150 ppm; at least 200 ppm; at least 250 ppm; at least 300 ppm; at least 350 ppm; at least 400 ppm; at least 450 ppm; at least 500 ppm; at least 550 ppm; at least 600 ppm; at least 650 ppm; at least 700 ppm; at least 750 ppm; at least 800 ppm; at least 850 ppm; at least 900 ppm; at least 950 ppm; or at least 1000 ppm, where at least some (an effective amount of) Zn and Ga are present, when both Zn and Ga are utilized as the corrosion resistant additives.

In some embodiments, the effective amount of corrosion resistant additive is not greater than 5 ppm; not greater than 10 ppm; not greater than 15 ppm; not greater than 20 ppm; not greater than 50 ppm; not greater than 100 ppm; not greater than 150 ppm; not greater than 200 ppm; not greater than 250 ppm; not greater than 300 ppm; not greater than 350 ppm; not greater than 400 ppm; not greater than 450 ppm; not greater than 500 ppm; not greater than 550 ppm; not greater than 600 ppm; not greater than 650 ppm; not greater than 700 ppm; not greater than 750 ppm; not greater than 800 ppm; not greater than 850 ppm; not greater than 900 ppm; not greater than 950 ppm; or not greater than 1000 ppm, where not greater than some (an effective amount of) Zn and Ga are present, when both Zn and Ga are utilized as the corrosion resistant additives:

In one or more of the aforementioned embodiments, the amount of Zn as a corrosion resistant additive as an individual addition is not greater than 0.05 wt. % of the corrosion resistant alloy.

In one or more of the aforementioned embodiments, the effective amount of corrosion resistant additive of Zn is at least 20 ppm; at least 50 ppm; at least 100 ppm; at least 150 ppm; at least 200 ppm; at least 250 ppm; at least 300 ppm; at least 350 ppm; at least 400 ppm; at least 450 ppm; at least 500 ppm. In some embodiments, the effective amount of corrosion resistant additive of Zn is not greater than 20 ppm; not greater than 50 ppm; not greater than 100 ppm; not greater than 150 ppm; not greater than 200 ppm; not greater than 250 ppm; not greater than 300 ppm; not greater than 350 ppm; not greater than 400 ppm; not greater than 450 ppm; not greater than 500 ppm.

In some embodiments, the effective amount of corrosion resistant additive is not greater than 5 ppm; not greater than 10 ppm; not greater than 15 ppm; not greater than 20 ppm; not greater than 50 ppm; not greater than 100 ppm; not greater than 150 ppm; not greater than 200 ppm; not greater than 250 ppm; not greater than 300 ppm; not greater than 350 ppm; not greater than 400 ppm; not greater than 450 ppm; not greater than 500 ppm; not greater than 550 ppm; not greater than 600 ppm; not greater than 650 ppm; not greater than 700 ppm; not greater than 750 ppm; not greater than 800 ppm; not greater than 850 ppm; not greater than 900 ppm; not greater than 950 ppm; or not greater than 1000 ppm, where not greater than some (an effective amount of) Zn and Ga are present, when both Zn and Ga are utilized as the corrosion resistant additives.

In one or more of the aforementioned embodiments, the amount of Ga as a corrosion resistant additive as an individual addition is not greater than 0.06 wt. % of the corrosion resistant alloy.

In one or more of the aforementioned embodiments, the amount of Ga as a corrosion resistant additive as an individual addition is not greater than 0.0 wt. % of the corrosion resistant alloy.

In one or more of the aforementioned embodiments, the effective amount of corrosion resistant additive of Ga is at least 5 ppm; at least 10 ppm; at least 15 ppm; at least 20 ppm; at least 50 ppm; at least 100 ppm; at least 150 ppm; at least 200 ppm; at least 250 ppm; at least 300 ppm; at least 350 ppm; at least 400 ppm; at least 450 ppm; at least 500 ppm; at least 550 ppm; or at least 600 ppm. In some embodiments, the effective amount of corrosion resistant additive of Ga is not greater than 5 ppm; not greater than 10 ppm; not greater than 15 ppm; not greater than 20 ppm; not greater than 50 ppm; not greater than 100 ppm; not greater than 150 ppm; not greater than 200 ppm; not greater than 250 ppm; not greater than 300 ppm; not greater than 350 ppm; not greater than 400 ppm; not greater than 450 ppm; not greater than 500 ppm, not greater than 550 ppm; or not greater than 600 ppm.

In one or more of the aforementioned embodiments, the corrosion resistant aluminum alloy is configured with the corrosion resistant additive(s) in an effective amount such that the aluminum alloy has an improved corrosion resistance as compared to an aluminum alloy without such corrosion resistant additives, when measured in accordance with an electrochemical cell test.

In some embodiments, an effective amount of the corrosion resistant additive is at least 5 ppm to not greater than 600 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 10 ppm to not greater than 300 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 5 ppm to not greater than 100 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 5 ppm to not greater than 50 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 20 ppm to not greater than 100 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 20 ppm to not greater than 50 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 1000 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 700 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 500 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 300 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 200 ppm.

In some embodiments, an effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 100 ppm.

In some embodiments, an effective amount of corrosion resistant additive is at least 20 ppm to not greater than 500 ppm of each additive, where the total amount of corrosion resistant additive is not greater than 1000 ppm.

In some embodiments, an effective amount of corrosion resistant additive is not greater than 1000 ppm, where at least some corrosion resistant additive is present.

In some embodiments, an effective amount of corrosion resistant additive is not greater than 500 ppm, where at least some corrosion resistant additive is present.

In some embodiments, an effective amount of corrosion resistant additive is not greater than 250 ppm, where at least some corrosion resistant additive is present.

In some embodiments, an effective amount of corrosion resistant additive is not greater than 100 ppm, where at least some corrosion resistant additive is present.

In some embodiments, an effective amount of corrosion resistant additive is not greater than 50 ppm, where at least some corrosion resistant additive is present.

In some embodiments, an effective amount of corrosion resistant additive is not greater than 20 ppm, where at least some corrosion resistant additive is present.

In any of the foregoing embodiments, the corrosion resistant additive is Zn and Ga in equal amounts.

In any of the foregoing embodiments, the corrosion resistant additive is Zn and Ga, with a greater amount of Zn than Ga.

In any of the foregoing embodiments, the corrosion resistant additive is Zn and Ga, with a lesser amount of Zn than Ga.

In any of the foregoing embodiments, the alloy further comprises not greater than 3 wt. % Mg.

In any of the foregoing embodiments, the alloy further comprises not greater than 0.04 wt. % Fe.

In any of the foregoing embodiments, the alloy further comprises not greater than 0.03 wt. % Fe.

In any of the foregoing embodiments, the alloy further comprises not greater than 0.02 wt. % Fe.

In any of the foregoing embodiments, the alloy further comprises not greater than 0.01 wt. % Fe.

As used herein, the phrase “the aluminum alloy” means an aluminum alloy selected from the group consisting of series of aluminum alloys registered with the Aluminum Association and unregistered variants of the same, as defined by the Aluminum Association document “International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys” (2009). In some embodiments, the aluminum alloy is a 1xxx series aluminum alloy. In some embodiments, the aluminum alloy is a 3xxx series aluminum alloy (e.g. 3002, 3102). In some embodiments, the aluminum alloy is a 5xxx series aluminum alloy. In some embodiments, the aluminum alloy is selected from the group consisting of a 1xxx series aluminum alloy, a 3xxx series aluminum alloy, and a 5xxx series aluminum alloy.

As used herein, “unavoidable impurities” means the presence of an undesirable component. As a non-limiting example, an unavoidable impurity is present in a quantity or amount that is low enough to not change a desired property and/or characteristic (i.e. below a threshold to modify the corrosion resistance of the corrosion resistant alloy and/or reduce the corrosion resistance above a certain margin of improvement when compared to the baseline material evaluated in an electrochemical cell test).

In some embodiments, the aluminum electrode alloy may comprise a 5252 aluminum alloy with an effective amount of a corrosion resistant additive.

The aluminum electrode alloy may comprise a 5005 aluminum alloy with an effective amount of a corrosion resistant additive.

The aluminum electrode alloy may comprise a 5xxx series aluminum alloy with an effective amount of a corrosion resistant additive.

The aluminum electrode alloy may comprise a 3xxx series aluminum alloy with an effective amount of a corrosion resistant additive.

The aluminum electrode alloy may comprise a 1xxx series aluminum alloy with an effective amount of a corrosion resistant additive.

In the embodiment, the baseline aluminum electrode alloy includes not greater than 60 ppm Fe, approximately 2.5 wt. % Mg, an effective amount corrosion resistant additive and remaining balance being aluminum and unavoidable impurities/minor components.

As described above, in some embodiments, the aluminum electrode alloy may comprise from 0.006 to 0.040 wt. % Fe. In some embodiments, the aluminum electrode alloy may comprise from 0.006 to 0.02 wt. % Fe. In some embodiments, the aluminum electrode alloy may comprise from 0.006 to 0.01 wt. % Fe.

As described above, in some embodiments, the aluminum alloy with corrosion resistance comprises from 0.01 to 3.0 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 3.0 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 2.0 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.9 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.8 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.7 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.6 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.5 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.4 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.3 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.2 wt. % Mg. In some embodiments, the aluminum alloy with corrosion resistance comprises from 0.1 to 1.1 wt. % Mg.

As described above, in some embodiments, the aluminum electrode alloy comprises from 0.01 to 3.0 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.05 to 3.0 wt. % Mg. In some embodiments, the electrode alloy comprises from 0.1 to 3.0 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 2.0 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.9 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.8 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.7 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.6 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.5 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.4 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.3 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.2 wt. % Mg. In some embodiments, the aluminum electrode alloy comprises from 0.1 to 1.1 wt. % Mg.

In one embodiment, a method for producing an aluminum electrode alloy product comprises the steps of selecting an aluminum alloy having the aforementioned composition, producing the solid aluminum alloy, wherein the producing step may comprise any casting method, and forming (e.g. rolling, forging) the aluminum alloy into a wrought structure.

In some embodiments, the aluminum alloy is configured as a foil, sheet, plate, disc, block, and combinations thereof. In some embodiments, the aluminum alloy product is configured as an extruded product, a cast product, a die cast product, a wrought product, or the like.

In some embodiments, the improved corrosion resistance of various embodiments of the aforementioned alloys was demonstrated in the electrochemical cell presented in FIG. 1. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention. Further, some features may be exaggerated to show details of particular components.

The figures constitute a part of this specification and include illustrative embodiments of the present invention and illustrate various objects and features thereof. In addition, any measurements, specifications and the like shown in the figures are intended to be illustrative, and not restrictive. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention is intended to be illustrative, and not restrictive.

Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrases “in one embodiment” and “in some embodiments” as used herein do not necessarily refer to the same embodiment(s), though it may. Furthermore, the phrases “in another embodiment” and “in some other embodiments” as used herein do not necessarily refer to a different embodiment, although it may. Thus, as described below, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention.

In addition, as used herein, the term “or” is an inclusive “or” operator, and is equivalent to the term “and/or,” unless the context clearly dictates otherwise. The term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of “a,” “an,” and “the” include plural references. The meaning of “in” includes “in” and “on”.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a schematic view of an example of an electrochemical cell that is configured for use in conjunction with Example 1 and Example 2, to evaluate the corrosion of electrodes in an electrolyte, in accordance with quantifying corrosion resistance with one or more of the present embodiments.

FIG. 2 provides experimental data obtained with the electrochemical cell of FIG. 1, utilized to evaluate the corrosion (i.e. quantified via the volume of hydrogen generation) of 6 different alloys, in comparison to a baseline/control. In some embodiments, one or more of the aluminum alloy compositions described allows for an improved corrosion resistance as compared to a conventional aluminum composition, when evaluated as an electrode in an electrochemical cell.

FIG. 3 provides experimental data obtained with the electrochemical cell of FIG. 1, utilized to evaluate the corrosion (i.e. quantified via the volume of hydrogen generation) of 2 different alloys, in comparison to a baseline/control. In some embodiments, one or more of the corrosion resistant aluminum alloy compositions described herein allows for a high iron content (e.g. 200 ppm or greater) of an iron content, in combination with corrosion resistant additives, which provides (1) an improved corrosion resistance as compared to a high-iron content electrode alloy without such additives and (2) a comparative corrosion resistance in line with the baseline (which as a low to no Iron content), as demonstrated in an electrochemical cell of FIG. 1.

DETAILED DESCRIPTION Examples

The following examples are intended to illustrate the invention and should not be construed as limiting the invention in any way.

Example 1—Forming Aluminum Alloy Samples

Aluminum alloys, having the compositions shown in Table 1, are cast as ingots, rolled to the desired thickness, and machined into disks (samples) having the desired thickness and a diameter, with a sufficient cross-sectional surface area to provide a viable testing surface for immersion into an electrochemical cell, schematically depicted in FIG. 1, for the evaluation and assessment of corrosion within the range of operating conditions of the cell (e.g. time, temperatures, current efficiency, etc.).

TABLE 1 Composition of Ex. 1 Alloys (in wt. %) Total amount of Hydrogen Released by Alloy: Comparing Baseline Material to Gallium/Zinc (with 2.5% Mg) Total volume of H₂ released per sample. It is noted, the Control and all six samples evaluated had 2.5 wt. % Mg and an iron content of 20 ppm Fe. Addition amount Sample (ppm) Name Type Ga Zn Control Comparative None None Alloy 1 Sample 1 Alloy 2 10 10 Sample 2 Alloy 3 50 60 Sample 3 Alloy 4 130 150 Sample 4 Alloy 5 230 290 Sample 5 Alloy 6 500 500 Sample 6 Alloy 7 0 1900

After casting, the disks formed of the Control and Samples 1-6 were corrosion tested in an electrochemical cell, as described below.

Example 2—Testing the Aluminum Alloy Samples

The Control and Samples 1-6 were tested for corrosion resistance (hydrogen generation) via an electrochemical cell system designed to simulate anode conditions in an electrochemical cell. The electrochemical cell consists of a counter electrode and an aluminum electrode (the control or sample) submerged in an aqueous electrolyte. The electrochemical cell is equipped with a mass-flow meter for measuring hydrogen gas evolved from the aluminum electrode. Current is applied on the aluminum electrode, through the electrolyte, into the counter electrode.

The samples and control were tested according to the following procedure. A predefined temperature-and-current step control program was applied to the cell so that the hydrogen evolution rate was measured over a set range of operating temperatures, i.e. between room temperature and 100° C. and over a set of current densities, ranging from 0 to 300 mA/cc².

The samples and control were run under identical conditions including electrolyte temperature, applied current, and test duration. Results are generated based on hydrogen generation, by accumulating the overall amount of hydrogen measured by the mass flow meter. Without being bound by a particular mechanism theory, it is believed that the overall amount of hydrogen generated by the system corresponds to the corrosion reaction (undesired reaction). Thus, the less hydrogen produced, the more corrosion resistant the alloy is that is being evaluated.

Samples 1-4 all provided a lower overall amount of hydrogen generation than the control. Sample 5 (not shown) was observed to corrode quickly and a measurement quantifying hydrogen generation was not obtained. Sample 6 did not perform better than the Control.

Example 3: Testing of the Aluminum Sample Alloys, Evaluating Iron Content

TABLE 2 Composition of Ex. 3 Alloys (in wt. %) Total amount of Hydrogen Released by Alloy: Comparing Baseline Material to Gallium/Zinc (with 2.5% Mg) Total volume of H₂ released per sample. Addition amount Sample (ppm) Name Type Fe Content Ga Zn Baseline/Control Comparative low iron content None None Alloy 1 (<30 ppm Fe) Comparative Alloy 2 high iron content None None Sample (200 ppm Fe) CR Al Electrode Alloy 3 high iron content 20 20 Sample (200 ppm Fe)

It is noted that all three samples (Control/Baseline, Comparative Sample, and CR Al Electrode) had a Mg content of 2.5 wt. %, while the Control/Baseline and Comparative Sample had no/no purposeful addition of Zn or Ga. The Control (baseline), Comparative Samples and CR Al Electrode Sample were tested for corrosion resistance via an electrochemical cell system and procedure described in Example 2.

All three tests were run under identical conditions including electrolyte temperature, applied current, and test duration. Results are generated based on hydrogen generation, by accumulating the overall amount of hydrogen measured by the mass flow meter. Without being bound by a particular mechanism or theory, it is believed that the overall amount of hydrogen generated by the system corresponds to the corrosion reaction (undesired reaction). Thus, the less hydrogen produced, the more corrosion resistant the alloy under evaluation is.

The three electrode compositions were as follows:

-   -   (1) Baseline/Control: Included approximately 2.5 wt. % Mg, low         iron content (<30 ppm Fe), no corrosion resistant additives, the         balance being aluminum and unavoidable impurities.     -   (2) Comparative Sample: Included 2.5 wt. % Mg, high iron content         (200 ppm Fe), no corrosion resistant additives, the balance         being aluminum and unavoidable impurities.     -   (3) Corrosion Resistant Aluminum Electrode Sample: Included 2.5         wt. % Mg, high iron content (200 ppm Fe), corrosion resistant         additives (20 ppm Ga, 20 ppm Zn), the balance being aluminum and         unavoidable impurities. (It is noted that the Comparative Sample         and the Corrosion Resistant Aluminum Electrode Sample underwent         a post-casting heat treatment for a sufficient time and         sufficient temperature to homogenize the iron present in the         sample.)

With reference to FIG. 3, it is readily observed that the Corrosion Resistant Aluminum Electrode Sample exhibited substantially similar hydrogen generation as the baseline, even with a high iron content (e.g. 200 ppm). In contrast, the Comparative Sample with high iron and no corrosion resistant additives exhibited much greater hydrogen generation values than either the Baseline/Control or the Corrosion Resistant Aluminum Alloy Electrode.

While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that many modifications may become apparent to those of ordinary skill in the art. Further still, the various steps may be carried out in any desired order (and any desired steps may be added and/or any desired steps may be eliminated).

Aspects of the invention will now be described with reference to the following numbered clauses:

1. An aluminum alloy composition comprising: a corrosion resistant aluminum alloy selected from the group consisting of: a 1xxx series aluminum alloy; a 3xxx series aluminum alloy; and a 5xxx series aluminum alloy; wherein the corrosion resistant aluminum alloy includes: not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; an effective amount of a corrosion resistant additive; and the balance being aluminum.

2. The aluminum alloy composition of clause 1, wherein the corrosion resistant additive is present in an amount such that the corrosion resistant aluminum alloy has an improved corrosion resistance as compared to an aluminum alloy without the corrosion resistant additive, when measured in accordance with an electrochemical cell test.

3. The aluminum alloy composition of any preceding clause, wherein: the corrosion resistant additive is selected from the group consisting of: Zn, Ga, and combinations thereof; the corrosion resistant aluminum alloy includes unavoidable minor components; the unavoidable minor components are present as a function of alloying the corrosion resistant aluminum alloy; and the corrosion resistant additive is present in an amount to provide an aluminum electrode alloy with improved corrosion resistance as compared to an aluminum electrode alloy without such corrosion resistant additive, when measured in accordance with an electrochemical cell test.

4. The aluminum alloy composition of any preceding clause, wherein: the corrosion resistant additive is selected from the group consisting of: Zn, Ga, and combinations thereof; the corrosion resistant aluminum alloy includes unavoidable minor components; the unavoidable minor components are present as a function of alloying the corrosion resistant aluminum alloy; and the corrosion resistant additive is present in an amount to provide an aluminum anode alloy with improved corrosion resistance as compared to an aluminum anode alloy without such corrosion resistant additive, when measured in accordance with an electrochemical cell test.

5. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant additive is selected from the group consisting of: Zn, Ga, and combinations thereof.

6. The aluminum alloy composition of any preceding clause, wherein: the corrosion resistant aluminum alloy includes not greater than 0.05 wt. % of the corrosion resistant additive; the corrosion resistant additive is present in the corrosion resistant aluminum alloy at the effective amount; and the corrosion resistant additive is selected from the group consisting of: Zn, Ga, and combinations thereof.

7. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant aluminum alloy includes not greater than 0.002 wt. % of the corrosion resistant additive.

8. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant aluminum alloy includes at least 0.002 wt. % to not greater than 0.025 wt. % of the corrosion resistant additive.

9. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant aluminum alloy includes at least 0.005 wt. % to not greater than 0.0250 wt. % of the corrosion resistant additive.

10. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant aluminum alloy includes at least 0.01 wt. % to not greater than 0.05 wt. % of the corrosion resistant additive.

11. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant aluminum alloy includes at least 0.015 wt. % to not greater than 0.03 wt. % of the corrosion resistant additive.

12. The aluminum alloy composition of any preceding clause, wherein, when Zn and Ga are utilized in combination, the amount of corrosion resistant additive is not greater than 0.1 wt. %.

13. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant additive is Zn.

14. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant additive is Ga.

15. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant additive is Zn and Ga.

16. The aluminum alloy composition of any preceding clause, wherein, when both Zn and Ga are utilized as the corrosion resistant additive, the effective amount of corrosion resistant additive is at least 20 ppm to not greater than 1000 ppm.

17. The aluminum alloy composition of any preceding clause, wherein: the corrosion resistant additive includes Zn; and the amount of Zn as the corrosion resistant additive as an individual addition is not greater than 0.05 wt. % of the corrosion resistant alloy.

18. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant additive includes Zn present in an amount of: at least 20 ppm to not greater than 500 ppm.

19. The aluminum alloy composition of any preceding clause, wherein: the corrosion resistant additive includes Ga; and the amount of Ga as the corrosion resistant additive as an individual addition is not greater than 0.05 wt. % of the corrosion resistant alloy.

20. The aluminum alloy composition of any preceding clause, wherein the corrosion resistant additive includes Ga present in an amount of: at least 20 ppm to not greater than 500 ppm.

21. The aluminum alloy composition of any preceding clause, wherein the effective amount of the corrosion resistant additive is at least 20 ppm to not greater than 100 ppm.

22. The aluminum alloy composition of any preceding clause, wherein the effective amount of the corrosion resistant additive is at least 20 ppm to not greater than 50 ppm.

23. The aluminum alloy composition of any preceding clause, wherein the effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 1000 ppm.

24. The aluminum alloy composition of any preceding clause, wherein the effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 700 ppm.

25. The aluminum alloy composition of any preceding clause, wherein the effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 500 ppm.

26. The aluminum alloy composition of any preceding clause, wherein the effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 300 ppm.

27. The aluminum alloy composition of any preceding clause, wherein the effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 200 ppm.

28. The aluminum alloy composition of any preceding clause, wherein the effective amount of the corrosion resistant additive is at least 50 ppm to not greater than 100 ppm.

29. The aluminum alloy composition of any preceding clause, wherein: the effective amount of the corrosion resistant additive is at least 20 ppm to not greater than 500 ppm of at least one of Zn and Ga; and a total amount of corrosion resistant additive is not greater than 1000 ppm.

30. The aluminum alloy composition of any preceding clause, wherein: the effective amount of the corrosion resistant additive is not greater than 1000 ppm; and at least some corrosion resistant additive is present.

31. The aluminum alloy composition of any preceding clause, wherein: the effective amount of the corrosion resistant additive is not greater than 500 ppm; and at least some corrosion resistant additive is present.

32. The aluminum alloy composition of any preceding clause, wherein: the effective amount of the corrosion resistant additive is not greater than 250 ppm; and at least some corrosion resistant additive is present.

33. The aluminum alloy composition of any preceding clause, wherein: the effective amount of the corrosion resistant additive is not greater than 100 ppm; and at least some corrosion resistant additive is present.

34. The aluminum alloy composition of any preceding clause, wherein: the effective amount of the corrosion resistant additive is not greater than 50 ppm; and at least some corrosion resistant additive is present.

35. The aluminum alloy composition of any preceding clause, wherein: the effective amount of the corrosion resistant additive is not greater than 20 ppm; and at least some corrosion resistant additive is present.

36. The aluminum alloy composition of any preceding clause, wherein: the corrosion resistant additive is Zn and Ga; and Zn and Ga are present in equal amounts.

37. The aluminum alloy composition of any preceding clause, wherein: the corrosion resistant additive is Zn and Ga; and Zn is present in a greater amount than Ga.

38. The aluminum alloy composition of any preceding clause, wherein: the corrosion resistant additive is Zn and Ga; and Zn is present in a lesser amount than Ga. 

What is claimed is:
 1. An aluminum alloy composition comprising: a corrosion resistant aluminum alloy selected from the group consisting of: a 1xxx series aluminum alloy; a 3xxx series aluminum alloy; and a 5xxx series aluminum alloy; wherein the corrosion resistant aluminum alloy includes: not greater than 0.04 wt. % Fe; not greater than 3 wt. % Mg; and an effective amount of a corrosion resistant additive.
 2. The aluminum alloy composition of claim 1, wherein the corrosion resistant additive is present in an amount such that the corrosion resistant aluminum alloy has an improved corrosion resistance as compared to an aluminum alloy without the corrosion resistant additive, when measured in accordance with an electrochemical cell test.
 3. The aluminum alloy composition of claim 1, wherein: the corrosion resistant aluminum alloy includes not greater than 0.1 wt. % of the corrosion resistant additive; and the corrosion resistant additive is present in the corrosion resistant aluminum alloy at the effective amount.
 4. The aluminum alloy composition of claim 3, wherein the corrosion resistant aluminum alloy includes at least 0.002 wt. % of the corrosion resistant additive.
 5. The aluminum alloy composition of claim 3, wherein the corrosion resistant aluminum alloy includes at least 0.005 wt. % of the corrosion resistant additive.
 6. The aluminum alloy composition of claim 3, wherein the corrosion resistant aluminum alloy includes at least 0.01 wt. % of the corrosion resistant additive.
 7. The aluminum alloy composition of claim 3, wherein the corrosion resistant aluminum alloy includes at least 0.015 wt. % of the corrosion resistant additive.
 8. The aluminum alloy composition of claim 4, wherein the corrosion resistant aluminum alloy includes not greater than 0.07 wt. % of the corrosion resistant additive.
 9. The aluminum alloy composition of claim 4, wherein the corrosion resistant aluminum alloy includes not greater than 0.05 wt. % of the corrosion resistant additive.
 10. The aluminum alloy composition of claim 4, wherein the corrosion resistant aluminum alloy includes not greater than 0.03 wt. % of the corrosion resistant additive.
 11. The aluminum alloy composition of claim 4, wherein the corrosion resistant aluminum alloy includes not greater than 0.025 wt. % of the corrosion resistant additive.
 12. The aluminum alloy composition of claim 4, wherein the corrosion resistant aluminum alloy includes not greater than 0.02 wt. % of the corrosion resistant additive.
 13. The aluminum alloy composition of claim 4, wherein the corrosion resistant aluminum alloy includes not greater than 0.01 wt. % of the corrosion resistant additive.
 14. The aluminum alloy composition of claim 4, wherein the corrosion resistant aluminum alloy includes not greater than 0.005 wt. % of the corrosion resistant additive.
 15. The aluminum alloy composition of claim 1, wherein the corrosion resistant additive is selected from the group consisting of Zn, Ga, and combinations thereof.
 16. The aluminum alloy composition of claim 15, wherein the corrosion resistant aluminum alloy comprises from 20 ppm to 500 ppm of Zn, or from 20 to 500 ppm of Ga, or both.
 17. The aluminum alloy composition of claim 16, wherein Zn and Ga are present in equal amounts.
 18. The aluminum alloy composition of claim 16, wherein Zn is present in a greater amount than Ga.
 19. The aluminum alloy composition of claim 16, wherein Zn is present in a lesser amount than Ga.
 20. The aluminum alloy composition of claim 1, wherein: the corrosion resistant aluminum alloy includes unavoidable minor components; and the unavoidable minor components are present as a function of alloying the corrosion resistant aluminum alloy. 